KR20030048109A - Sulfur-absorbent bed and fuel processing assembly incorporating the same - Google Patents

Abstract

A fuel processing system 10 comprising an improved sulfur removal assembly 40. The fuel processing system 10 includes at least one fuel processor 20 adapted to produce hydrogen gas 22 from water and a carbon-containing feedstock such as at least one hydrocarbon or alcohol. The sulfur-removing aggregate 40 includes a sulfur-absorbent bed containing a sulfur-absorbing material, such as a low temperature altering catalyst (LTS), modified to remove or reduce concentrations of sulfur compounds from the carbon-containing feedstock 24. .

Description

Sulfur-absorbing bed and fuel processing assembly comprising same {SULFUR-ABSORBENT BED AND FUEL PROCESSING ASSEMBLY INCORPORATING THE SAME}

Purified hydrogen is used in the manufacture of many products, including metals, edible fats and oils, and semiconductors and microelectronics. Purified hydrogen is also an important fuel source for many energy conversion devices. For example, cells use purified hydrogen and oxidants to generate potentials. A process known as steam reforming produces chemical reactions with hydrogen and any byproducts or impurities. Subsequent purification processes can be used to remove undesired impurities to provide hydrogen purified enough for cell application.

In steam reforming, the reaction is with steam and a carbon-containing feedstock in the presence of a reforming catalyst. Steam reforming requires high operating temperatures, for example between 250 ° C. and 900 ° C., mainly to produce hydrogen and carbon dioxide, and less carbon monoxide is also formed. Traces of unreacted reactants and traces of by-products can also be formed from steam reforming. Examples of suitable carbon-containing feedstocks include, but are not limited to, alcohols (such as methanol or ethanol) and hydrocarbon fuels (such as methane, propane, gasoline, diesel or kerosene).

Almost all hydrocarbon fuels typically contain varying concentrations of organic sulfur compounds in the range of about 3 ppm to about 300 ppm. These sulfur compounds will be activity inhibitors of conventional steam reforming (and autothermal reforming) catalysts and must be removed from hydrocarbon fuels before being transported to the reforming catalyst.

Typically, the concentration of sulfur compounds is reduced by passing the hydrocarbon feedstock through a bed containing absorbent material modified to reduce the concentration of these sulfur compounds in the feedstock. Some known absorbers are based on zinc oxide. These materials are not perfectly effective at removing organic sulfur compounds because of the poor reactivity of some organic sulfur compounds such as thiophenes and organic sulfides. Zinc oxide is generally effective at removing hydrogen sulfide from hydrocarbon feedstocks, but not at removing other sulfur-containing compounds. The other absorbent material is based on nickel oxide. Nickel typically forms compounds with most sulfur compounds, although they require higher operating temperatures. However, the hydrocarbon feedstock tends to form coke on the nickel, which reduces the reactivity of the nickel because the reaction site is blocked by the coke.

Summary of the Invention

The present invention relates to a fuel processing system comprising an improved sulfur-removing assembly. The fuel processing system includes at least one fuel processor adapted to produce hydrogen gas from water and a carbon-containing feedstock such as at least one hydrocarbon or alcohol. Sulfur-removing aggregates include sulfur-absorbing beds containing sulfur-absorbing materials that have been modified to remove or reduce concentrations of sulfur compounds from carbon-containing feedstocks, such as low temperature altering (LTS) catalysts.

Many of the features of the present invention will become apparent to those skilled in the art with reference to the following detailed description and the accompanying drawings, which illustrate, by way of example, preferred embodiments incorporating the principles of the invention.

The present invention relates generally to fuel processing systems and more particularly to fuel processing systems that produce hydrogen gas from reformed feedstock using reforming catalysts.

1 is a schematic diagram of a fuel processing system according to the present invention.

2 is a schematic diagram of another aspect of the fuel processing system of FIG. 1.

3 is a schematic diagram of another embodiment of the fuel processing system of FIG. 1.

4 is a schematic diagram of a sulfur-removing aggregate according to the present invention.

5 is a schematic diagram of the FIG. 4 aggregate including the heating aggregate.

6 is a schematic view of the FIG. 4 assembly including a heating assembly.

7 is a schematic diagram of the FIG. 4 aggregate including the heating aggregate.

8 is a schematic view of the FIG. 4 assembly including a heating assembly.

9 is a schematic diagram of the fuel processing system of FIG. 1 including a controller adapted to monitor the state of the sulfur-removing assembly.

10 is a schematic diagram of the FIG. 9 fuel processing system having multiple sulfur-absorbing beds.

11 is a schematic of a steam reformer that may be used with the sulfur-removing device of the present invention.

12 is a schematic diagram of another embodiment of the FIG. 11 steam reformer.

13 is a schematic diagram illustrating a cell stack.

14 is a schematic representation of a sulfur-removing aggregate according to the present invention.

15 is a schematic of a sulfur-removing aggregate according to the present invention.

16 is a schematic diagram of a sulfur-removing aggregate according to the present invention.

17 is a schematic representation of a sulfur-removing aggregate according to the present invention.

18 is a schematic representation of a sulfur-removing aggregate according to the present invention.

A fuel processing system according to the present invention is shown in FIG. 1 and indicated generally at 10. System 10 includes at least one fuel processor 20 adapted to produce hydrogen product 22 from feedstock 24. The feedstock 24 comprises a carbon-containing feedstock 28 such as at least one hydrocarbon or alcohol. Examples of suitable hydrocarbons include methane, propane, natural gas, diesel, kerosene, gasoline and the like. Examples of suitable alcohols include methanol, ethanol, and polyols such as ethylene glycol and propylene glycol.

In any preferred embodiment, the feedstock 24 further comprises water 26, which is to be delivered to the fuel processor independently of the carbon-containing feedstock or to be delivered as the same flow stream as the carbon-containing feedstock. Can be. 1 shows that feedstock 24 includes separated water and carbon-containing feedstock. This configuration may be used for alcohol or other water-miscible feedstock 28, but is typically used when the carbon-containing feedstock is a hydrocarbon. To illustrate that water and carbon-containing feedstock may be mixed before being transported to the fuel processor 20, the raw material 24 is divided into water 26 and a carbon-containing feedstock using FIG. 28) and may indicate that separate water and carbon-containing feedstock are mixed before delivery to the fuel processor.

The fuel processor 20 includes a hydrogen-generating region 30 that produces hydrogen products 22 from the feed stream 24. The fuel processor 20 may generate hydrogen gas from the water 26 and the carbon-containing feedstock 28 through any suitable mechanism. Examples of suitable mechanisms include steam reforming and autothermal reforming, where a reforming catalyst is used to generate hydrogen gas from the carbon-containing feedstock 28 and water 26. Another suitable mechanism for producing hydrogen gas is catalytic partial oxidation of alcohols or hydrocarbons. Typically, the hydrogen-generating region will comprise at least one catalyst bed 32, such as a reforming catalyst bed or a partial oxidation catalyst bed. In the steam reformer, the hydrogen-generating zone 30 may be referred to as reforming zone 30 and the catalyst bed 32 may be referred to as a reforming catalyst bed or a steam reforming catalyst bed. In a similar manner, in the autothermal reformer, the hydrogen-generating region 30 may be referred to as the autothermal reforming region 30 and the catalyst bed 32 may be referred to as the autothermal reforming catalyst bed.

System 10 includes, but not necessarily, at least one battery stack 34. Each cell stack 34 includes at least one that is modified to generate current from hydrogen gas, such as generating stream 22 from fuel processor 20, and typically a number of cells 36. Examples of suitable cells include proton exchange membrane (PEM) cells and alkaline cells. Some or all of stream 22 may additionally or alternatively be transported for use in another hydrogen-consuming process via suitable conduits, burned for fuel / heating, or stored for later use. have. Examples of suitable storage mechanisms include pressurized tanks and hydride beds.

An illustrative example of the battery stack is shown in FIG. Stack 34 (and the individual cells 36 contained therein) comprises a positive electrode region 130 and a negative electrode region 132, which are separated by an electrolyte membrane or barrier 134 through which hydrogen ions can pass. It is. The anode and cathode regions include anode and cathode electrodes 136 and 138, respectively. The positive electrode region 130 of the cell stack receives hydrogens 22. Cathode region 132 receives airflow 140 and emits cathode air outlet 142 in which oxygen is partially or substantially consumed. Electrons liberated from hydrogen gas cannot pass through the barrier 134 but must pass through the external circuit 144 so that the generated current not only meets the electrical load imposed by one or more devices 146, but also It can also be used to run fuel processing systems.

The anode region 130 is periodically purged and emits a purge stream 147, which may contain hydrogen gas. Alternatively, hydrogen gas is continuously discharged from the anode region of the cell stack and recycled. Current is generated by the cell stack 34 to meet the load as applied from the device 146. Also shown in FIG. 2 is the air delivery assembly 148, which has been modified to carry the air stream 152 to the cell stack 34, such as to the negative electrode region 132. The air delivery assembly 148 is systematically illustrated in FIG. 13 and can take any suitable form. Within the scope of the present invention, the air delivery assembly 148 may be a single device or a separate device. Similarly, the air delivery assembly 148 may also provide air flow to the fuel processor 20, or the fuel processor 20 may include its own air delivery system.

System 10 further includes a sulfur-removing aggregate 40 modified to remove sulfur compounds from carbon-containing feedstock 28 to produce a feedstock 28 'having a reduced sulfur compound concentration. In an embodiment of a feedstock comprising water and a carbon-containing feedstock, the aggregate 40 is used to remove these compounds from the feedstock containing the carbon-containing feedstock before or after mixing with the water 26. It should be understood. For example, FIG. 1 uses a dashed line to graphically represent a single stream containing a carbon-containing feedstock 28 and water 26, and water 26 and a carbon-containing feedstock 28. FIG. The timing of mixing the separated raw materials containing the same is illustrated. Also within the scope of the present invention the carbon-containing feedstock and water may not be mixed until after they have been evaporated.

1 shows that the sulfur-removing assembly 40 is separated from the fuel processor 20. "Separation" means that the sulfur-removing system is in fluid communication with the fuel processor but physically away from the fuel processor. However, within the scope of the present invention, the aggregate 40 may be directly connected to the fuel processor or contained within the fuel processor sheath 42, as shown in FIGS. 2 and 3.

As shown in FIG. 4, the aggregate 40 includes at least one sulfur-absorbing bed 44 through which the carbon-containing feedstock passes before being delivered to the reforming region of the fuel processor. Although a single sulfur-absorbent bed 44 is shown in FIG. 4, the number and size of the beds 44 can vary, and therefore, the assembly 40 can have two or more parallel (see FIG. 10) and / or in series (FIG. 14). It is to be understood that two or more beds may be included, including beds. Each bed 44 includes a sulfur-absorbing material 46 modified to remove sulfur compounds from the carbon-containing feedstock to produce a feedstock 28 'having a reduced concentration of sulfur compounds. Preferably, the sulfur absorbent 46 does not promote the formation of methane or coke at the operating conditions of the aggregate 40.

As used herein, a "bed" refers to a relatively packed surface that is positioned or supported such that sulfur-absorbent 46 can contact the carbon-containing feedstock 28 as well as packed columns or tubes through which the carbon-containing feedstock passes. This broad and relatively low pressure drop is meant to include a wide range of other structures or areas of other structures. Examples of other beds within the scope of the present invention include filters impregnated or otherwise contained with sulfur-absorbing material 46 and porous supports on which sulfur-absorbing material 46 is supported. Examples of these supports include ceramic materials, nets or other textiles or screens, and porous materials such as corrugated materials.

Similarly, while systematically illustrating the assembly 40 with at least one bed 44 contained therein, this systematic description should not be interpreted as requiring or excluding the outer frame of the bed. Therefore, within the scope of the present invention, the bed may comprise a jacket or sheath surrounding the frame of the bed and away from it, and the bed may also be formed without such a jacket.

An example of a suitable sulfur-absorber 46 is a low temperature change (LTS) catalyst. Since LTS catalysts are easily inhibited by sulfur compounds, they are effective in removing these compounds from carbon-containing feedstocks. LTS catalysts are also more effective than zinc oxide in removing sulfur compounds from carbon-containing feedstocks because they are more reactive than zinc oxide. Moreover, the LTS catalyst does not promote the formation of coke at the operating conditions of the assembly 40.

LTS catalysts are typically compositions of copper and zinc and are available in a variety of forms and shapes. Suitable shapes for use in the absorbent bed are pellets. Another example is an LTS catalyst extruded into the desired shape, such as an LTS catalyst in granular or powder form. Typically, the copper and zinc containing LTS catalyst will comprise about 10-90% copper (I) and / or copper (II) oxide and about 10-90% zinc oxide. As used herein, "copper oxide" means copper oxide (I) and / or copper oxide (II). The LTS catalyst may further comprise other materials, such as 0-50% alumina. Other examples of LTS catalysts may include those containing 20-60% copper oxide, 20-50% copper oxide, or 20-40% copper oxide. Others include copper oxide in the range described above and 20-60% zinc oxide, 20-50% zinc oxide, or 30-60% zinc oxide. Other LTS catalysts contain chromium. LTS catalysts may also include other sulfur-absorbers, inert and / or support materials. Examples of suitable LTS catalysts are manufactured by ICI Chemicals & Polymers, Ltd., Billingham, England and are sold under the trade name 52-1. This LTS catalyst contains about 30% copper (II) oxide, about 45% zinc oxide and about 13% alumina. Another example of a suitable LTS catalyst is G66B manufactured and sold by Sud-Chemie, Inc., Louisville, KY. Suitable other LTS catalysts include K3-100, manufactured and sold by BASF Corporation.

It should be understood that other LTS catalysts may also be used, provided that they meet the criteria described below. Suitable LTS catalysts should be effective to remove sulfur compounds from the carbon-containing feedstock 28 at operating temperatures below about 350 ° C., and promote the conversion of carbon monoxide and water at temperatures below about 350 ° C. to obtain hydrogen and carbon dioxide. It should be able to be activated and generally inhibited by sulfur concentrations of about 1-10 ppm at temperatures below about 350 ° C.

Indeed, the carbon-containing feedstock passes through a sulfur-absorbing bed 44 containing LTS catalyst pellets. The bed operates in a temperature range of about 20 ° C. to about 400 ° C., and preferably in a temperature range of about 100 ° C. to about 400 ° C. Organic sulfur compounds (and hydrogen sulfide, if present) are reacted with the LTS catalyst pellets under these conditions to form stable sulfides of copper and zinc, resulting in a stream with reduced sulfur concentration while retaining sulfur. The advantage of using LTS catalysts is that neither copper nor zinc is particularly active in the formation of carbon (coke) from hydrocarbons.

Preferably, the aggregate 40 comprises, or is in heat transfer with, the heating assembly 50. "Heat transfer" means that the heating aggregate carries heat to the sulfur-removing assembly, whether the heating assembly is included in the sulfur-removing assembly or modified to carry a heated flow there away from the sulfur-removing assembly. I mean. For example, a heater or combustion zone that is separate from the sulfur removal assembly may be used to heat the sulfur removal assembly (or at least the bed or beds therein). Alternatively, or in addition, the bed can be heated by conveying hot effluent to the sulfur-removing aggregate.

In FIG. 5, an example of a suitable heating assembly 50 is shown in the form of an electric heater 52 that heats the bed 44. Heater 52 may take any suitable form and is powered by current 54 from an external source or from cell stack 34. Another example of a suitable heating assembly 50 is the combustion chamber 56 that burns the fuel stream 58 to produce a heated combustion gas stream 60 that can be used to heat the bed or beds in the desulfurization assembly. It is shown in Figure 6 in the form. Combustion chamber 56 may include a burner, combustion catalyst, ignition device or before ignition, or other suitable ignition source. Fuels 58 may be any suitable combustibles, such as fuels from external sources, portions of hydrogen gas 22, combustible byproducts from fuel processor 20, or combinations thereof.

Heating assembly 50 may also take the form of one or more heating streams that heat the sulfur-removing assembly, or its bed (s), via heat exchange. An illustrative example of a heater assembly including heat exchange flow is shown in FIGS. 7 and 8. In FIG. 7, the heat exchange stream 66 carries the heated fluid 68 to the sulfur-removing aggregate 40 and the stream 70 removes the fluid from the aggregate 40. Streams 66 and 70 may form a continuous fluid circulation loop, or alternatively, stream 70 may deliver the fluid contained therein to a downstream destination for use, storage or disposal. have. In FIG. 8, the sulfur-absorbing bed 44 includes one or more passageways 72 through which heated flow can pass to heat the bed. As shown, the bed 44 includes a plurality of passages 72 through which the heated flow flow 74 flows. Also shown in FIG. 8 is any dispensing composite 76 that distributes fluid to stream 74 between passages. Examples of suitable heat exchange fluids include, but are not limited to, air, water, oil, ethylene glycol, propylene glycol and silicone fluids.

The heating assembly 50 can additionally, or alternatively, heat the bed 44 indirectly by heating the carbon-containing feedstock 28 carried there. Any of the heating assemblies described and illustrated above can be used to heat the feedstock 28. This is illustrated in FIG. 4, where the heating assembly 50 heats the feedstock 28 systematically.

Bed 44 is periodically replaced and refilled to maintain the sulfur-absorbing properties of sulfur-absorbing material 46 contained therein. Typically, the bed will be used to purify the hydrocarbon fuel until the sulfur absorption capacity of the bed is at least 80% and less than about 98%. It is to be understood that the bed can be replaced and refilled even when the capacity% is different. When the bed reaches a defined capacity, or range of capacity, the bed is offline for replacement or recharging.

When using a single bed 44, it is preferred that the fuel processing system 10 includes an appropriate controller 80 that measures when the capacity reaches the desired percentage and triggers a user-notification event in response thereto. (But not required). An illustrative example of a suitable controller 80 is shown in FIG. 9 which includes a detector 82 adapted to measure the bed sulfur absorption capacity% when the bed is operating. Such measurements can be made directly or indirectly by any suitable sensing device. For example, the detector can be modified to directly measure the sulfur content in the bed. When the sulfur content of the feedstock 28 is known, the detector 82 is a timer modified to indirectly measure the sulfur content by measuring the operating time while the bed is in use or the volume of feedstock that has passed through the bed, respectively. It may take the form of a flow meter. For purposes of illustration, a number of suitable detectors and possible detector locations are shown in FIGS. 9 and 10. Detector 82 is communicated with controller 80 via delivery link 83, which may be any suitable wired or wireless mechanism capable of one-way or two-way delivery.

In response to the measured capacity level compared to the storage threshold level, the controller generates a system response, such as control signal 85, which may be any suitable wired or wireless mechanism capable of one-way or two-way transmission, similar to link 83. can do. When the measurement level is below the storage threshold level, no reaction occurs because the sulfur absorbent still has sufficient sulfur absorption capacity. When the measurement level reaches or exceeds the threshold level, the controller activates the user-notification device 84, which is an audio and / or visual device. As indicated above, the controller 80 may include a storage area 87, or at least one storage device, adapted to store at least one threshold value for the at least one sulfur-absorbent bed.

Preferably, the threshold level is chosen such that no immediate response of the user is required before the sulfur-absorber has a capacity that is too low to effectively remove the sulfur compound from the feedstock 28. More specifically, the controller preferably operates the user-notifying device before the sulfur absorbent reaches its capacity to effectively remove sulfur from the feedstock 28. For example, the controller can activate the user-notification device 84 when the measurement level is 80%, 85% or 90% of the sulfur-absorber capacity. It is to be understood that any desired threshold level may be used, and that level is merely an illustration of an appropriate level.

The controller 80 may include one or more threshold levels for the measured dose levels to be compared. For example, if the measured capacity level of the absorbent 46 exceeds a lower threshold, the user-notification device 84 is activated to notify the user that the absorbent has approached the sulfur compound itself capacity and needs to be replaced or recharged. can do. However, if the measured dose level reaches a higher threshold selected from or near that of the dose level at which the absorbent can no longer effectively remove sulfur compounds from the feedstock 28, then the controller may then turn off some or all of the fuel processing system. By operating a system control reaction such as closing or preventing the feedstock from being transferred to the fuel processor, the reforming catalyst is prevented from being inhibited by the sulfur compound containing feedstock.

As discussed, the sulfur-removing aggregate 40 can include one or more sulfur-absorbent beds 44. An illustrative embodiment of such an aggregate is shown in FIG. 10. As shown, the sulfur-removing aggregate 40 comprises a pair of sulfur-absorbing beds, i.e., bed 44 'and bed 44 ". It should be understood that any number of beds including two or more beds may be used. The beds can also be connected in series and / or in parallel. As shown, the controller 80 includes a detector 82 adapted to measure the working capacity of each bed 44 to determine if the capacity of the bed exceeds one or more storage threshold levels or threshold values.

In some applications, it may be desirable for the aggregate 40 to include at least one "extra" bed that does not operate at any particular time. However, if a particular bed needs to be recharged or replaced, the extra bed may be online and the bed used may be offline. Once offline, the bed used is replaced and / or refilled, but there is no need to close or offline the fuel processing system. In FIG. 10, the controller 80 is in communication with a valve assembly 86 that selectively transports feedstock to one or more beds 44. As shown, the valve assembly 86 is adapted to carry feedstock to the bed 44 '. However, in response to a control signal from the controller 80, such as when the working capacity of the bed 44 'has reached a threshold level, the valve assembly 86 will instead feed the feedstock into the bed 44 ". To carry on. The valve assembly 86 can additionally or alternatively be controlled by hand and can also be located inside or outside the assembly 40. After separation from the flow of carbon-containing feedstock 28, bed 44 'can be replaced or refilled. One suitable mechanism for recharging a bed, more particularly sulfur-absorbent 46 in the bed, is to heat the absorbent in the presence of oxygen or air to convert the sulfide therein into an oxide, which is then reduced to recover the underlying metal. It is.

As discussed, any suitable fuel processor 20 utilizing reforming catalyst 32 may be used, such as steam reformers and autothermal reformers. Examples of suitable steam reformers are disclosed in US Pat. Nos. 5,861,137 and 5,997,594, and US Patent Application Serials 09 / 190,917 and 09 / 802,361, the disclosures of which are hereby incorporated by reference. An example of a suitable fuel processor 20 is shown in FIG. 11 in the form of a steam reformer 100. The reformer 100 is a separate stream containing water 26 and a carbon-containing feedstock 28 ′ from hydrogen-containing streams, or mixed gas streams 104, from the feed stream 24 illustrated in FIG. 11. Reforming, or hydrogen-generating region 30, to produce a. Since hydrogen-containing streams typically contain impurities, they are carried to a separation zone, or purge zone 106, to purify the stream. In the separation zone 106, the hydrogen-containing stream is separated into one or more byproducts 108 and the purified hydrogen stream 110 forming the hydrogenated product 22 by any suitable pressure-induced separation process. As discussed, hydrogen products 22 may be conveyed to cell stack 34. Alternatively, or in addition, some or all of stream 22 may be delivered to a suitable storage device, such as a hydride bed or storage tank, or may be transported for use in a process requiring purified hydrogen gas. Can be.

An example of a structure suitable for use in the isolation region 106 is a membrane module 112 containing one or more hydrogen permeable metal membranes 114. Examples of suitable membrane modules formed from a plurality of hydrogen-selective metal membranes are disclosed in US Pat. No. 6,221,117, the entire disclosure of which is referred to herein. In this application, a plurality of planar membranes are typically associated with a membrane module having a flow channel through which impurity gas streams are carried to the membrane, purified gas streams are recovered from the membrane and by-products are removed from the membrane. do. Gaskets, such as flexible graphite gaskets, are used to seal around the raw material and penetrate the flow channels.

The thin planar hydrogen-permeable membrane is preferably composed of a palladium alloy, most specifically a mixture of palladium mixed with 35% to 45% by weight of copper. Such membranes are typically formed from thin foils of about 0.001 inches thick. However, within the scope of the present invention, the membrane may be formed from hydrogen-selective metals and metal alloys other than those discussed above and the membrane may have a thicker or thinner thickness than discussed above. For example, the membrane can be made thinner in proportion to the increase in hydrogen flow rate. The hydrogen-permeable membrane may be arranged in any suitable structure, such as arranged in pairs around a general transmission channel as disclosed in the referenced patent application. Hydrogen permeable membranes or membranes can take on other structures as well as tubular structures.

Another example of a suitable pressure-separation process is pressure swing absorption (PSA). Therefore, region 106 may alternatively comprise a suitable structure for effecting pressure swing absorption.

The reformer 100 may further include a cleaning region 116 as shown in FIG. 12. The cleaning zone 116 receives the hydrogen-rich stream 110 from the separation zone 106 and reduces or eliminates the concentration of the composition that may damage the cell stack 34, such as carbon monoxide and carbon dioxide, and thereby removes the stream. Further purify. The cleaning zone 116 includes a suitable structure for reducing or eliminating the concentration of the selected composition in the stream 110. For example, it is desirable to include at least one methanation catalyst bed 118 when the product stream is to be used in another apparatus that will be damaged if the PEM cell stack or stream contains more than a given concentration of carbon monoxide or carbon dioxide. can do. Bed 118 converts carbon monoxide and carbon dioxide into methane and water, both of which will not damage the PEM cell stack. The cleaning zone 116 may also include another hydrogen-generating device 120, such as another reforming catalyst bed, to convert any unreacted feedstock to hydrogen gas. In this embodiment, it is preferred that the second reforming catalyst bed is located upstream of the methanation catalyst bed in order not to reintroduce carbon dioxide or carbon monoxide located downstream of the methanation catalyst bed.

In the foregoing discussion, only the specific examples of sulfur-absorbing material 46 suitable for use with the sulfur-absorbent bed 44 according to the present invention have been focused. Within the scope of the present invention, the LTS catalyst bed may be used alone or in combination with a sulfur removal bed as illustrated systematically at 160 in FIG. 15. Examples of bed 160 include conventional sulfur-absorbing material 162 containing beds such as zinc oxide, nickel oxide, iron oxide, and / or activated charcoal. Another example of a suitable bed 160 is desulfurization catalyst bed 164. Desulfurization catalysts are used to convert sulfur compounds, which are not generally absorbed into conventional sulfur-absorbers 162, to hydrogen sulfide through a process called hydrogen sulfide. In this process, the carbon-containing feedstock is chemically blended with mercaptan sulfur, organic sulfur such as thiophene, which are not easily removed by conventional sulfur-absorbers in contact with the catalyst in an operating environment containing high temperature and partial hydrogen high pressure. Sulfur-containing compounds, such as sulfides and disulfides, are converted to hydrogen sulfide. Hydrogen sulfide can then be removed by conventional sulfur-absorbers.

Although FIG. 15 shows that bed 160 precedes bed 44, the reverse order may also be used as indicated in FIG. 16. Similarly, as illustrated systematically in FIG. 17, bed (s) 44 may precede or follow bed 160, and bed 160 may have the same or different structure. As a further example, FIG. 18 systematically illustrates that bed 44 may include sulfur-removing material such as material 162 as well as sulfur-removing material 46.

The present invention is applicable to all fuel processing and cell systems in which the feedstock contains a carbon-containing feedstock that may contain or may be contaminated with sulfur-containing compounds.

It is believed that the foregoing disclosure includes many unique inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments disclosed and illustrated herein are not to be considered in a limiting sense, as many variations are possible. The subject matter of the present invention includes all new and unknown combinations and subcombinations of the various elements, features, functions and / or properties disclosed herein. Similarly, it is to be understood that claims enumerating “one” or “first” elements or equivalents thereof include one or more combinations of these elements, neither requiring nor excluding two or more of these elements.

The following claims represent any new and unknown combinations and subcombinations relating to one of the disclosed inventions in particular. The invention, which is embodied within other combinations and subcombinations of features, functions, elements and / or properties, may be claimed through modification of the claims or the submission of new claims in this or related application. Such modified or new claims, whether they relate to different inventions or to the same invention, whether different from the scope of the existing claims, wider, narrower or the same, are included within the subject matter of the disclosed invention. It can also be considered to be.

Claims (60)

A sulfur-removing aggregate comprising at least one sulfur-absorbent bed modified to receive a stream containing a carbon-containing feedstock and sulfur compounds, wherein the bed is a sulfur-absorber modified to reduce the concentration of sulfur compounds in the stream. Wherein the sulfur-absorber is modified to promote conversion of carbon monoxide and water at temperatures below about 350 ° C. to yield hydrogen gas and carbon dioxide; And A fuel processing system comprising a fuel processor adapted to receive a feedstock comprising a carbon-containing feedstock from a sulfur-removing aggregate and to produce hydrogen products containing hydrogen gas therefrom. 10. The fuel processing system of claim 1, wherein the sulfur-absorbent is selected from the group of materials that do not promote methane formation from the carbon-containing feedstock when the bed operates at temperatures below about 400 ° C. The fuel processing system of claim 1, wherein the sulfur-absorbing material is selected from the group of materials that do not promote coke formation from the carbon-containing feedstock when the bed operates at temperatures below about 400 ° C. 3. The fuel processing system of claim 1, wherein the sulfur-absorbing material is more reactive than zinc oxide in removing sulfur compounds from the carbon-containing feedstock at a temperature in the range of about 100 ° C to about 400 ° C. The fuel processing system of claim 1, wherein the sulfur-absorbing material is modified to absorb organic sulfur compounds. The fuel processing system of claim 1, wherein the sulfur-absorbing material is selected from the group of materials that are inhibited when exposed to sulfur compounds. 7. The fuel processing system of claim 6, wherein the sulfur-absorbing material is selected from the group of materials that are inhibited upon exposure to sulfur compounds present at concentrations ranging from 1-10 ppm at temperatures below about 350 < 0 > C. 10. The fuel processing system of claim 1, wherein the sulfur-absorbing material comprises 10-90% copper oxide. 9. The fuel processing system of claim 8, wherein the sulfur-absorbing material comprises 20-60% copper oxide. 10. A fuel processing system according to claim 9, wherein the sulfur-absorbing material further comprises zinc oxide. The fuel processing system of claim 1, wherein the sulfur-absorbing material comprises chromium. 10. The fuel processing system of claim 1, wherein the bed operates at a temperature in the range of 20 ° C to about 400 ° C. 13. The fuel processing system of claim 12, wherein the fuel processing system comprises a heating assembly adapted to heat the at least one sulfur-absorbent bed to a temperature in the range of about 100 ° C to about 400 ° C. 2. The fuel processing system of claim 1, wherein the sulfur-removing aggregate comprises a plurality of sulfur-absorbent beds containing sulfur-absorbents. 15. The process of claim 14, wherein the sulfur-removing aggregates do not receive a stream containing a carbon-containing feedstock and at least one sulfur-absorbent bed does not receive a portion of the stream containing a carbon-containing feedstock. And a valve assembly adapted to selectively carry less than sulfur-absorbing beds. 2. The sulfur absorbent bed of claim 1, wherein each sulfur absorbent bed containing sulfur absorbent material has a sulfur absorbent capacity, and further the fuel processing system includes at least one detector modified to measure the percent capacity of each bed operating. A fuel processing system, characterized in that. 2. The user of claim 1, wherein each sulfur-absorbing bed containing sulfur-absorbing material has a sulfur absorption capacity, and further wherein the fuel processing system measures and responds to when the threshold value corresponding to a predetermined volume percentage is reached. Further comprising a controller adapted to cause a notification event. 18. The fuel processing system of claim 17, wherein the controller is adapted to send a control signal to the user-notifying device upon measuring the bed operating beyond the threshold. 18. The fuel processing system of claim 17, comprising at least one detector modified to measure the percentage of each bed capacity of the bed on which the controller operates. 20. The fuel treatment of claim 19, wherein each sulfur-absorbing bed containing sulfur-absorbing material comprises a sensor adapted to measure the percentage of each bed sulfur absorption capacity of the bed in which the communication with the controller is made and operated. system. 18. The fuel processing system of claim 17, wherein the controller comprises a storage area for storing at least one threshold value for each sulfur-absorbent bed containing sulfur-absorbents. 22. The system of claim 21, wherein the controller comprises a storage area that stores at least lower and higher threshold values for each sulfur-absorbent bed containing sulfur-absorbents, wherein the sulfur operates at a capacity above the lower threshold value. -As soon as one of the beds containing absorbent material is measured, the controller is modified to send the first control signal to the user-notifying device and further contains a sulfur-absorbent operating at a capacity above the higher threshold value. The controller is adapted to send a second control signal to the user-notifying device as soon as one of the measurements is made. 23. The fuel processing system of claim 22, wherein the user-notifying device is modified to produce different responses in response to receiving first and second control signals. 10. The fuel processing system of claim 1, wherein the sulfur-removing aggregate further comprises at least one sulfur-removing region adapted to remove sulfur compounds from carbon-containing feedstocks other than sulfur-absorbers. . 25. The fuel processing system of claim 24, wherein at least one sulfur-removing region is modified to remove sulfur compounds by hydrodesulfurization. 10. The fuel processing system of claim 1, wherein the carbon-containing feedstock comprises at least one hydrocarbon. 2. The fuel processing system of claim 1, wherein the carbon-containing feedstock comprises at least one alcohol. The feedstock of claim 1 wherein the feedstock comprises water and the fuel processor includes a reforming zone having at least one reforming catalyst bed adapted to produce hydrogen gas-containing streams from the feedstock via a reforming reaction, further comprising water A fuel processing system, wherein the lean product is formed from a hydrogen gas containing stream. 29. The hydrogen gas-containing stream of claim 28, wherein the hydrogen gas-containing stream further comprises another gas, and further wherein the fuel processor contains the hydrogen gas-containing stream at least substantially a hydrogen-rich stream containing hydrogen gas and at least a substantial portion of the other gas. A fuel processing system comprising a separation zone for separating by-products. 30. The fuel processing system of claim 29, wherein the separation zone is modified to separate the hydrogen gas containing streams into hydrogen-rich and byproduct streams through a pressure driven separation process. 31. The method of claim 30, wherein the separation zone comprises at least one hydrogen-permeable membrane positioned to contact the hydrogen gas-containing stream, wherein the hydrogen-rich stream is formed from a portion of the hydrogen gas-containing stream that permeates through the membrane. And the byproducts are formed from a portion of the hydrogen gas containing streams that do not pass through the membrane. 32. The fuel processing system of claim 31, further comprising a cell stack adapted to receive at least a portion of the hydrogen products and generate current therefrom. 32. The fuel processing system of claim 31, wherein the at least one membrane comprises at least one palladium and palladium alloy. 34. The fuel of claim 33, wherein each pair of such membranes comprises a plurality of hydrogen-permeable membranes arranged in pairs, the permeable channels defining between them, from which a hydrogen-rich class is produced. Processing system. 10. The fuel processing system of claim 1, further comprising a cell stack adapted to receive at least a portion of the hydrogen products and generate current therefrom. A sulfur-removing aggregate comprising at least one sulfur-absorbent bed modified to receive a stream containing a carbon-containing feedstock and sulfur compounds, wherein the bed is a sulfur-absorber modified to reduce the concentration of sulfur compounds in the stream. Wherein the sulfur-absorber is selected from the group of materials that do not promote the formation of methane or coke from the carbon-containing feedstock when the bed is operated at temperatures below about 400 ° C. Is a sulfur-removing aggregate that is modified to absorb organic sulfur compounds; And A fuel processor adapted to receive a feedstock comprising a carbon-containing feedstock from a sulfur-removing aggregate and to produce hydrogen products containing hydrogen gas therefrom, the feedstock comprising a stream containing a carbon-containing feedstock and water A reforming zone containing at least one reforming catalyst bed for producing a mixed gas stream containing hydrogen gas and other gases from the stream, and further comprising at least substantial hydrogen gas in the mixed gas stream through a pressure driven separation process. And a separation zone separating the hydrogen-rich stream containing and the byproduct stream containing at least a substantial portion of the other gases. 37. The fuel processing system of claim 36, wherein the sulfur-absorbing material is more reactive than zinc oxide in removing sulfur compounds from the carbon-containing feedstock at temperatures in the range of about 100 ° C to about 400 ° C. 37. The fuel processing system of claim 36, wherein the sulfur-absorbing material is selected from the group of materials that are inhibited when exposed to sulfur compounds. 39. The fuel processing system of claim 38, wherein the sulfur-absorbing material is selected from the group of materials that are inhibited when exposed to sulfur compounds present at concentrations in the range of 1-10 ppm at temperatures below about 350 ° C. 37. The fuel processing system of claim 36, wherein the sulfur-absorber comprises 10-90% copper oxide. 41. The fuel processing system of claim 40, wherein the sulfur-absorbing material comprises 20-60% copper oxide. 42. The fuel processing system of claim 41, wherein the sulfur-absorbing material further comprises zinc oxide. 37. The fuel processing system of claim 36, wherein the sulfur-absorbing material comprises chromium. 37. The fuel processing system of claim 36, wherein the bed operates at a temperature in the range of 20 ° C to about 400 ° C. 45. The fuel processing system of claim 44, wherein the fuel processing system comprises a heating assembly adapted to heat the at least one sulfur-absorbent bed to a temperature in the range of about 100 ° C to about 400 ° C. 37. The fuel processing system of claim 36, wherein the sulfur-removing aggregate comprises a plurality of sulfur-absorbing beds containing sulfur-absorbing material. 47. The method of claim 46, wherein the sulfur-removing aggregates do not receive a stream containing a carbon-containing feedstock and at least one sulfur-absorbent bed does not receive a portion of the stream containing a carbon-containing feedstock. And a valve assembly adapted for selective delivery to less sulfur-absorbent beds. 37. The sulfur absorbent bed of claim 36, wherein each sulfur absorbent bed containing sulfur absorbent material has a sulfur absorbent capacity, and further wherein the fuel processing system includes at least one detector modified to measure the percent capacity of each bed operating. A fuel processing system, characterized in that. 37. The user of claim 36, wherein each sulfur-absorbing bed containing sulfur-absorbing material has a sulfur absorption capacity, and further wherein the fuel processing system measures and responds to the timing at which a threshold value corresponding to a defined volume percentage is reached. Further comprising a controller adapted to cause a notification event. 50. The fuel processing system of claim 49, wherein the controller is adapted to send a control signal to the user-notifying device upon measuring the bed operating beyond the threshold. 50. The fuel processing system of claim 49, comprising at least one detector modified to measure the percent of each bed capacity of the bed in which the controller operates. 52. The fuel treatment of claim 51, wherein each sulfur-absorbing bed containing sulfur-absorbing material comprises a detector adapted to measure the percentage of each bed sulfur absorption capacity of the bed in which the communication with the controller is made and operated. system. 50. The fuel processing system of claim 49, wherein the controller comprises a storage area for storing at least one threshold value for each sulfur-absorbent bed containing sulfur-absorbents. 54. The sulfur of claim 53, wherein the controller comprises a storage area that stores at least lower and higher threshold values for each sulfur-absorbent bed containing sulfur-absorbents, wherein the sulfur operates at a capacity above the lower threshold value. -As soon as one of the beds containing absorbent material is measured, the controller is modified to send the first control signal to the user-notifying device and further contains a sulfur-absorbent operating at a capacity above the higher threshold value. The controller is adapted to send a second control signal to the user-notifying device as soon as one of the measurements is made. 55. The fuel processing system of claim 54, wherein the user-notifying device is modified to produce different responses in response to receiving first and second control signals. The method of claim 36, wherein the separation region comprises at least one hydrogen-permeable membrane positioned to contact the hydrogen gas-containing stream, wherein the hydrogen-rich stream is formed from a portion of the hydrogen gas-containing stream that permeates through the membrane. And the byproducts are formed from a portion of the hydrogen gas containing streams that do not pass through the membrane. 59. The fuel processing system of claim 56, wherein the at least one membrane comprises at least one palladium and palladium alloy. 58. The fuel of claim 57, wherein each pair of such membranes comprises a plurality of hydrogen-permeable membranes arranged in pairs, the separation regions defining permeable channels therebetween, from which a hydrogen-rich class is produced. Processing system. 37. The fuel processing system of claim 36, further comprising a cell stack adapted to receive at least a portion of the hydrogen products and generate current therefrom. A steam reformer comprising a reforming zone modified to receive a feedstock comprising water and a carbon-containing feedstock and having at least one reforming catalyst bed producing hydrogen gas containing streams from the feedstock, upstream of the reforming zone. Steam reformer having a sulfur-removing aggregate comprising at least one sulfur-absorbing bed containing a low temperature altering catalyst modified to absorb sulfur-containing compounds from at least a portion of the feedstock prior to delivery to the reforming zone. .